1. Field of the Invention
With reference to the classification of art as established in and by the U.S. Patent and Trademark Office the present invention is believed to be found in the class entitled, "Plasticware Article or Earthenware Shaping or Treating Apparatus" (Class 425) and in particular in the subclass entitled, "Female Mold including Tamping means or means Utilizing Mold Motion to Distribute or Compact Stock therein" (Subclass 425).
2. Description of the Prior Art
Apparatus for centrifugally casting thermosetting plastics and the like are well known and have been shown in issued patents. Some prior art showings believed to be pertinent include U.S. Pat. No. 3,601,857 issued to Hampel on Aug. 31, 1971 which discloses materials for making a mold; U.S. Pat. No. 3,850,902 issued to Metcalfe, et al., on Nov. 29, 1974 disclosing a process for casting parts; U.S. Pat. No. 4,002,418 issued to Wallace on Jan. 11, 1977 and U.S. Pat. No. 4,034,955 also issued to Wallace on July 12, 1977. Each of these patents discloses apparatus for centrifugally casting parts and the clamping of the casting molds; U.S. Pat. No. 4,063,863 as issued to Hilmoe on Dec. 20, 1977 disclosing a centrifugal casting machine having a vacuum assist.
It is believed that none of the above identified prior art patents show or disclose the simple construction of the apparatus and method of applicant's invention or describe the improvements to the apparatus and methods for producing centrifugally cast parts from thermosetting plastics and the like.